A core-substituted naphthalene diimide fluoride sensor.

Area of Science:

• Supramolecular chemistry
• Analytical chemistry
• Organic synthesis

Background:

• Fluorescent sensors are crucial for detecting specific anions.
• Naphthalene diimide derivatives offer unique photophysical properties.
• Developing selective sensors for fluoride remains a challenge.

Purpose of the Study:

• To synthesize and characterize a novel fluorescent sensor based on a core-substituted naphthalene diimide.
• To investigate the sensor's selectivity and reactivity towards various anions, particularly fluoride.
• To explore the sensing mechanism in different solvent environments.

Main Methods:

• Synthesis of a core-substituted naphthalene diimide bearing a bis-sulfonamide group.
• Characterization of the synthesized compound using spectroscopic techniques.
• Fluoride ion sensing experiments in chloroform and DMSO, monitoring colorimetric and absorption changes.

Main Results:

• The synthesized sensor exhibits high fluorescence quantum yield (φ = 0.34).
• In chloroform, the sensor displays selective fluoride detection via a two-stage deprotonation mechanism, resulting in a colorimetric change.
• In DMSO, the sensor shows high selectivity for fluoride (K(a) ≈ 10^6 M⁻¹) with significant changes in absorption spectra.

Conclusions:

• The novel naphthalene diimide derivative functions as an effective and selective fluorescent sensor for fluoride ions.
• The sensor's response mechanism varies with the solvent, offering versatile detection capabilities.
• This work contributes to the development of advanced chemosensors for anion recognition.